Week 1: How do we measure psychopathology

Question 1

What do developmental psychopathologists measure

Answer 1

Psychopathology/symptoms
Predictors, correlates and consequences of psychopathology
Behavioral
Neural
Physiological
Neural
Cognitive

Question 2

Reliability

3 Things

Answer 2

How consistent it the measure?

Internal consistency:
Are reports on items measuring the construct consistent? If a measure is reliable, scores from people with the construct should be highly correlated with each other.

Test-retest reliability: Do we get the same answer on different occasions? Sometimes we would not expect to (mood) but if we think the construct is stable, we expect this.

Inter-rater reliability: Agreement between 2 people judging whether something is present or absent.
2 people using the same system should reach the same conclusion.

Question 3

Validity

2 things

Answer 3

Does the measurement assess what we want it to?

Convergent validity:
Are scores on the measure related to other measures or indicators of the same construct?

Discriminant validity:
Are the scores on the measure different from scores of measures designed to measure other constructs? If not, are the measuring the thing you designed thm to measure?

Question 4

Categorical vs Dimensional

Answer 4

Cat = difference in kind

Dim = difference in degree`

Question 5

Unstructured interviews

Answer 5

Clinician asks questions and arrives at diagnosis

Super common

Question 6

Unstructured interviews - problems

Answer 6

Challenges:
Less comprehensive - clinicians make diagnoses before they have heard all the info. May miss things.

Biases may affect diagnosis

Confirmation bias:
Tend to selectively collect information that confirms diagnosis they believe the patient has
Ignore disconfirmatory information

Use an availability heuristic:
Make decisions based on things that came up recently
eg if you diagnose ADHD this morning, might be more likely to do it again this PM.

Question 7

Semi-structured and structured interviews

Answer 7

Has a set of questions that are presented to the respondent

Improves comprehensiveness

Reduces bias

Semi-structured means the interviewer has a lot of leeway to ask follow up questions and means clinical judgement forms part of the diagnosis.

Structured - interview is strictly controlled
Can be done by a PC

Question 8

Unstructured vs semi or structured

Answer 8

Semi/structured are more reliable and valid

Can be used categorically or dimensionally (by tallying the symptoms)

Question 9

Disadvantages of semi or structured

Answer 9

Standard in research, rare in clinical work

Too long

Cant fit into the hours you have funding for

Need advanced training to do right

Question 10

Rating scales

Answer 10

Often used to measure continuously

Can be used categorically too

Short, no interviewer

Historically thought to be worse than interviews. Evidence suggests may not be true.

Raises the possibility that this could lead to standardized diagnoses, would be good (takes less time)

Question 11

Observations

Answer 11

May want to to observe behavior directly

Without training, hard to say if something is normative or not (eg tantrums in kids and moodiness in teens)

Observation provides access to the circumstances in which behavior occurs which can provide useful info

Question 12

Naturalistic observation

Answer 12

Natural environment
Very rich can see antecedent-behavior-consequence
ie if a behavior always gets the child’s way, it is obvious why they keep doing it

Question 13

Structured observation

Answer 13

Lab/clinic
Designed to see child’s response to a situation
You could give them an online game in which a “peer” provokes them but in reality its a confederate.

Question 14

Observation - Challenges

Answer 14

Feasibility - labor intensive

External validity - presence of observer chances behavior (not in young kids)
May not see the same results as “real world”

May be hard to see the behavior of interest:
Low base-rate (rare)

Covert:
eg relational aggression

Creative solutions have worked for this eg
wireless microphones
Provocation in labs

Question 15

Who do we get info from to assess?

Answer 15

Parents, children and teachers usually

Question 16

Disagreement among informants

Answer 16

Often do not agree - r from .2 to .4
Used to think this was error
BUT different informants provide reliable and valid responses
eg teacher report is reliable and correlates with other measures
Both show “good info”

Question 17

Why do informants disagree?

Different perspectives

Answer 17

(1) Different perspectives
Rater-specific factors (biases):
Maternal depression associated with overreporting behavioral problems
May see differences between school and mother if mother is overreporting

Legitimate differences in the meaning of behaviors across settings:
Parents/teachers interact with kids in different contexts and these may change the interpretation of behavior
Teachers may see assertive behavior as oppositional, parents might not

These differences may tell us important things about a child’s adaptation in different environments; they could ne struggling at school and not at home.

Question 18

Why do informants disagree?

Situation specificity

Answer 18

Children behave differently across different situations

These have different demands (school requires socializing, might be harder for a shy kid than home)

Inter-rater differences may capture real differences in behaviour in different settings

Parents and teachers may see different things

Question 19

Using data from multiple informants

and or

combine or keep seperate

Answer 19

You can combine date from different sources via the “and” rule or the “or” rule

“Or” rule:
Symptom is present if any informant says it is

“and” rule
Symptom is only present if all informants agree

Or symptom is most common

Neither captures the idea that differences between the two raters are valuable

Diagnosis as reported by a teacher may be different from that reported by a parent

Might be useful to keep parent’s, teacher’s and combined reports separate

Question 20

And or symptom rule

Answer 20

Symptom based are when you co bine symptoms ie

And = both parent and teacher say a symptom is present

Or = either parent or teacher say symptom is present

Or symptom is the most common

Question 21

And or diagnosis rule

Answer 21

Here the condition is diagnosed if

AND RULE

By adding up symptoms from the parents report you reach threshold for a diagnosis
AND
By adding up symptoms from the teacher’s report, you reach threshold
BOTH REPORTS MUST BE ABOVE THRESHOLD TO DIAGNOSE

OR RULE

By adding up symptoms from the parents report you reach threshold for a diagnosis
OR
By adding up symptoms from the teacher’s report, you reach threshold
ONLY ONE REPORT NEEDS TO BE ABOVE THRESHOLD TO DIAGNOSE